This patent application is based on U.S. provisional patent application No. 60/500,891, that was filed on Sep. 5, 2003.
The present invention relates to the field of electrical switchgear and more particularly to the field of switchgear fuses. In even greater particularity the present invention relates to an indicator mounted on a fuse housing body to give a visual indication that the fuse has been properly latched into the fuse mounting structure.
Fuses for electrical switchgear are typically attached to fuse handling hardware including an interrupter body at a first end and a pull ring assembly a the opposite end. The hardware is configured to positively support the fuse on a fuse mounting assembly which is often times pivotally mounted on a door or carrier such as within the switchgear housing. The interrupter body is generally configured to engage a latching mechanism which is part of the fuse mounting assembly. A set of “ears” are formed on the outside of the interrupter body and have a cam like surface inclined away from the axis of the fuse and body. The fuse and interrupter body are generally pivotally mounted within the mounting assembly such that as the interrupter body pivots to move the fuse into its proper position a spring loaded latch moves up the cam surface until the surface abruptly ends at a shoulder extending outwardly from the body, whereupon the latch is urged and against the interrupter body and helps to secure the fuse in the mounting assembly such that the entire assembly may be rotated into position to complete the electrical connection. The manipulation of the fuse is often accomplished with hotsticks or insulated gear as a safety precaution.
Occasionally the fuse and interrupter are not actually moved to a latched position in as much as the pull ring end of the fuse also engages an electrical contact and some times the fuse only appears to be latched in the mounting assembly due to frictional resistance of the latch or at the pull ring end. Improper seating of the fuse can lead to fuse failure and failure of the phase of the switchgear associated with the fuse. Accordingly, a need exists for an indicator that will visibly identify the fuse as being properly seated in the fuse mounting assembly.